Copper iodide (CuI) is a chemical compound with a bright yellow color. It forms when copper reacts with iodine, and it’s used in various applications, including organic synthesis and catalysis.
| IUPAC Name | Copper(I) Iodide |
| Molecular Formula | CuI |
| CAS Number | 7681-65-4 |
| Synonyms | Cuprous Iodide, Copper Monoiodide, Cuprous Iodide (1:1) |
| InChI | InChI=1S/Cu.HI/h;1H/q+1;/p-1 |
Copper Iodide Properties
Copper Iodide Formula
The chemical formula of cuprous iodide is CuI. It indicates that each unit of cuprous iodide consists of one copper atom (Cu) and one iodine atom (I). This simple formula represents the stoichiometry of the compound.
Copper Iodide Molar Mass
The molar mass of cuprous iodide (CuI) can be calculated by adding the atomic masses of its constituent elements. Copper has a molar mass of approximately 63.55 g/mol, while iodine has a molar mass of about 126.90 g/mol. Thus, the molar mass of CuI is approximately 190.45 g/mol.
Copper Iodide Boiling Point
Cuprous iodide does not have a well-defined boiling point since it undergoes decomposition before reaching its boiling point. Upon heating, it decomposes into copper metal and iodine gas, making it unsuitable for a traditional boiling point determination.
Copper Iodide Melting Point
Cuprous iodide’s melting point is relatively low compared to many other metal halides. It has a melting point of around 606 degrees Celsius (1123 degrees Fahrenheit). At this temperature, solid cuprous iodide converts into a molten liquid.
Copper Iodide Density g/mL
Cuprous iodide has a density of approximately 5.67 g/mL. This value represents the mass of cuprous iodide per unit volume. It indicates that cuprous iodide is relatively dense compared to some other inorganic compounds.
Copper Iodide Molecular Weight
The molecular weight of cuprous iodide, also known as the molar mass, is approximately 190.45 g/mol. It is the sum of the atomic weights of all the atoms present in one molecule of cuprous iodide (CuI).
Copper Iodide Structure
Cuprous iodide exists in various crystal structures, including alpha, beta, and gamma phases. The most common form is the alpha phase, which has a zinc blende structure. It forms a lattice of copper and iodine atoms.
Copper Iodide Solubility
Cuprous iodide’s solubility in different solvents varies. It is sparingly soluble in water, and its solubility can be increased by adding iodide ions. Organic solvents like ethanol can dissolve it more effectively than water.
| Appearance | Bright yellow solid |
| Specific Gravity | 5.67 g/mL |
| Color | Yellow |
| Odor | Odorless |
| Molar Mass | 190.45 g/mol |
| Density | 5.67 g/cm³ |
| Melting Point | 606°C (1123°F) |
| Boiling Point | Decomposes before boiling |
| Flash Point | Not applicable |
| Water Solubility | Sparingly soluble |
| Solubility | Soluble in organic solvents like ethanol and ether |
| Vapour Pressure | Not available |
| Vapour Density | Not available |
| pKa | Not available |
| pH | Not applicable |
Please note that some properties, such as flash point, vapour pressure, vapour density, pKa, and pH, are not applicable or not available for cuprous iodide due to its nature and properties.
Copper Iodide Safety and Hazards
Cuprous iodide poses certain safety hazards that should be taken into account during handling. It is essential to wear appropriate personal protective equipment (PPE) like gloves and goggles to avoid skin and eye contact. Inhalation of dust or fumes should be avoided as it may cause respiratory irritation. Cuprous iodide is moderately toxic if ingested and must not be consumed. Additionally, it is essential to work with cuprous iodide in a well-ventilated area to prevent the accumulation of vapors. Proper storage in tightly sealed containers away from incompatible substances is crucial to minimize potential hazards.
| Hazard Symbols | Irritant |
| Safety Description | Causes skin and eye irritation. Moderately toxic if ingested. Avoid inhalation. Use in a well-ventilated area. Wear appropriate PPE. |
| UN IDs | Not applicable |
| HS Code | Not applicable |
| Hazard Class | Not applicable |
| Packing Group | Not applicable |
| Toxicity | Moderately toxic if ingested |
Copper Iodide Synthesis Methods
Cuprous iodide can be synthesized using different methods. One common method for synthesizing cuprous iodide involves mixing finely powdered Cu with iodine and heating the mixture in a controlled environment. As the temperature increases, Cu reacts with iodine to form cuprous iodide.
Another approach entails adding copper oxide (CuO) or copper hydroxide (Cu(OH)2) to hydroiodic acid (HI) and heating the mixture. The reaction between the acid and the copper compound results in the formation of cuprous iodide.
Cuprous iodide can also be obtained by mixing a Cu salt, such as CuSO4, with a soluble iodide salt like potassium iodide (KI) in water. This reaction leads to the precipitation of cuprous iodide.
Furthermore, a double displacement reaction between a soluble Cu salt like copper sulfate and a soluble iodide salt like sodium iodide (NaI) in an aqueous solution yields solid cuprous iodide as a precipitate.
These synthesis methods offer various routes to obtain cuprous iodide, enabling its use in a wide range of applications in chemistry and industry.
Copper Iodide Uses
Cuprous iodide finds versatile applications in various fields due to its unique properties. Here are some of its prominent uses:
- Organic Synthesis: Cuprous iodide serves as a catalyst in organic reactions, promoting various coupling reactions like Ullmann, Sonogashira, and Glaser reactions.
- Semiconductors: It is employed in the production of semiconductors, specifically as a p-type semiconductor material.
- Photovoltaic Devices: Cuprous iodide is used in solar cells and photodetectors due to its photoconductivity and light-absorbing properties.
- Electroplating: It is utilized as an electrolyte additive in electroplating baths to enhance copper deposition.
- Pigments: Cuprous iodide’s bright yellow color makes it valuable as a pigment in the ceramic and glass industries.
- Anti-fouling Paint: It is an essential component in anti-fouling paints for marine applications.
- Chemical Reagents: Cuprous iodide is used in laboratories as a chemical reagent for various tests and experiments.
- X-ray Contrast Media: In medical imaging, cuprous iodide-based contrast agents are employed for X-ray examinations.
- Wood Preservative: Cuprous iodide protects wood from decay and insect infestations, making it useful in the timber industry.
- Fungicides: It acts as an effective fungicide, protecting crops and plants from fungal infections.
Cuprous iodide’s wide-ranging applications demonstrate its significance in numerous industries, ranging from electronics and photovoltaics to agriculture and medicine.
Questions:
Q: How to make copper iodide?
A: Cuprous iodide can be synthesized by reacting copper metal or copper oxide with iodine or by double displacement reactions using copper sulfate and potassium iodide.
Q: Is cuprous iodide soluble in water?
A: No, cuprous iodide (CuI2) is insoluble in water.
Q: What is the molecular equation for the reaction of copper II nitrate and potassium iodide?
A: The molecular equation is Cu(NO3)2 + 2KI → CuI2 + 2KNO3.
Q: What is the formula for cuprous iodide?
A: The formula for cuprous iodide is CuI2.
Q: Is copper (II) iodide insoluble?
A: Yes, cuprous (II) iodide (CuI2) is insoluble in water.
Q: Is it safe to mix copper sulfate and potassium iodide?
A: Mixing CaSO4 and potassium iodide can produce cuprous iodide, but caution should be exercised due to the reactivity of the chemicals involved.
Q: What is the name of the compound with the formula CUI2?
A: The compound with the formula CUI2 is cuprous (II) iodide.
Q: Is CUI2 a precipitate?
A: Yes, CUI2 can form a precipitate in certain reactions due to its low solubility in water.
Q: Is CUI2 soluble in water?
A: No, CUI2 is not soluble in water.
Q: Is CUI2 soluble?
A: No, CUI2 is not soluble in most common solvents.
Q: What makes CUI2 insoluble?
A: The low solubility of CUI2 is due to its strong ionic bond between copper and iodine, leading to limited dissociation in water.